Band-Limited Digital Predistortion with Band-Switching Feedback Architecture for 5G mmWave Power Amplifiers

This paper presents a novel band-limited digital predistortion (BL-DPD) with band-switching feedback architecture and update procedure for linearization of a wideband 5G mmWave power amplifier (PA). In the proposed BL-DPD, inside and outside of original input signal band in PA output are acquired alternately. This is done while keeping ADC bandwidth same as original input signal bandwidth, thus, avoiding increase in cost and energy consumption. It is demonstrated that the proposed BL-DPD achieves ACLR of -43.6/-42 dBc and EVM < 3% for Watt-class PA operating on a 256 QAM modulated 26 GHz OFDM signal with bandwidth of 800 MHz.